1. Field of the Invention
The present invention relates to a wireless communication system and a wireless communication apparatus which transmit and receives a signal by using a plurality of wireless apparatuses.
2. Related Art
Recently, an ad-hoc network comes under spotlight. In ad-hoc network, a plurality of terminals communicate without passing through a base station and an access point. In the ad-hoc network, the terminals exchange information by autonomously controlling communication. At this time, it is possible to exchange information with a terminal at a location where a transmission signal does not directly reach, by relaying the signal by another terminal.
A MIMO (Multi-Input Multi-output) transmission system comes under spotlight, too. The MIMO transmission transmits the signal from a plurality of transmission antennas to a plurality of reception antennas, and performs interference suppression and equalization at reception side, such as BLAST (Bell laboratory Layered Space-Time architecture) and a space-time coding. The BLAST has a feature in which transmission information is divided and transmitted in parallel from a plurality of antennas. The space-time coding has a feature in which although the same information is transmitted from a plurality of antennas, coding methods are different for each antenna.
In the network composed of a mobile terminal such as the ad-hoc network, since miniaturization of the apparatus is requested, it may be difficult to mount many types of apparatuses and to perform a complicated processing. Because of this, it is difficult to improve frequency availability, to increase transmission capacity, and to improve communication quality.